In conventional panoramic dental radiography, an X-ray source and camera extend from opposite sides of an arm which rotates slowly above the patient's head such that X-radiation from the X-ray source passing through the dental arch area is continuously received by the camera. The X-ray film within the camera is driven at a predetermined non-linear speed past a centrally disposed slot in a front panel of the camera. The patient may or may not be shifted during the orbiting of the X-ray source and camera about him. When the equipment is correctly adjusted and the patient properly disposed, one curved layer or curved plane of the dental arch area will be in focus while layers on either side thereof become progressively blurred as the distance from the layer in focus increases, i.e., a tomographic image of the desired layer is obtained.
That curved layer or plane in focus is commonly referred to as the focal trough, i.e., the selected sharp layer lying in a vertical curved plane having a horizontal dimension or width designed to portray radiographically, part of the bone of the maxilla, part of the bone of the mandible, and the teeth.
A clear image or view of the focal trough provides the dentist with extremely valuable diagnostic information. However, currently available apparatus do not provide sufficiently sharp images having adequately wide troughs, especially in the anterior region, nor do current techniques provide for rapid real time changes in focal trough locations or shapes as the image is formed on the oscilloscope display. In film systems, the image is not normally seen until after the patient exposure is completed since the image is recorded on X-ray film.
The present invention substantially overcomes the aforementioned disadvantages and weaknesses of the prior art by providing apparatus and methods which permit the dentist to observe real time displays of a plurality of different focal trough images simultaneously as the images are created, and wherein the created images may be controllably varied to provide optimum diagnostic information by simply adjusting knobs of associated electronic components. Additionally, hard copies of desired images can readily be made available.